1. Field of the Invention
The present invention relates to a laminated magnetic film, such as a so-called precipitation-type microcrystal soft-magnetic thin film, a method of manufacturing the laminated magnetic film and a magnetic head having the laminated magnetic film.
2. Description of the Related Art
In recent years, recording densities of signals have been raised in the magnetic recording field, thus resulting in that magnetic recording mediums, such as metal tapes, having great coercive force and high residual magnetic flux densities have been employed, the metal tape being manufactured by directly coating a non-magnetic support member with a ferromagnetic metal material. Under the circumstances, magnetic heads have been required to comprise a core made of a material having a high saturated magnetic flux density and high magnetic permeability.
To meet the foregoing requirement, a metal-in-gap type magnetic head (hereinafter called a MIG head) has been suggested which is structured such that ferrite is employed as a sub-core material and a metal magnetic film having a high saturated magnetic flux density is, as a main core material, formed on the ferrite layer so that a magnetic gap portion is formed by the metal magnetic film. The metal-in-gap type magnetic head is capable of satisfactorily recording and reproducing signals to and from a metal tape.
Under the circumstances in which the recording density has been raised considerably, the magnetic head of the above-mentioned type must be composed of a metal magnetic material having a high saturated magnetic flux density, with which a large recording magnetic field can be obtained, and exhibiting a soft magnetic characteristic in order to record and reproduce signals to and from a magnetic recording medium, such as the metal tape, having great coercive force.
Since a so-called precipitation type and microcrystal metal magnetic film containing Fe as the main component thereof has a high saturated magnetic flux density and excellent soft magnetic characteristic in the in-plane direction, the foregoing film has been put into practical use in place of the conventional metal magnetic material for making a magnetic head.
The precipitation-type microcrystal metal magnetic film is generally formed such that a non-crystalline film is formed; and then the film is subjected to heat treatment so that small crystal particles mainly composed of Fe are dispersed and precipitated. The precipitation-type microcrystal metal magnetic film is exemplified by Fe--Ta--N. The precipitation-type microcrystal metal magnetic film in the form of Fe--Ta--N has a high magnetic permeability equal to that of a soft magnetic amorphous film and a high saturated magnetic flux density equal to that of Fe. Therefore, it can be said that the precipitation-type microcrystal metal magnetic film is a metal magnetic material suitable to manufacture the above-mentioned magnetic head.
However, the precipitation-type microcrystal metal magnetic film involves crystal particles being dispersed and precipitated therein after it has been subjected to heat treatment. However, the precipitation-type microcrystal metal magnetic film encounters a difficulty in controlling the crystal orientation of microcrystal particles. That is, the precipitation-type microcrystal metal magnetic film involves precipitated microcrystal particles having a random crystalline orientation.
Therefore, if the precipitation-type microcrystal metal magnetic film is employed as the metal magnetic material for manufacturing a magnetic head, the soft magnetic characteristic in the direction of the thickness thereof is unsatisfactory despite excellent in-plane soft magnetic characteristic. Therefore, even if a magnetic head is manufactured by using the above-mentioned precipitation-type microcrystal metal magnetic film, the efficiency of the magnetic head is unsatisfactory, and a required improvement in reproduction output cannot be realized.